An experimental study of molecular and conformational order of the phosphatidylcholine molecule in the bilayer membrane is proposed. Furthermore, the effect of insertion of protein into the bilayer on that molecular and conformational order is to be investigated. A new multi-order parameter approach is to be applied to the interpretation of deuterium magnetic resonance spectra from specifically deuterated sites in the phospholipid molecules. From this approach one is able to obtain new information concerning restricted rotation of the phospholipid about its long molecular axis and added information concerning its time average conformation. This approach, combined with pulsed gradient NMR measurements of lipid self-diffusion will be used to study protein-lipid interactions in the bilayer. Specific models given for these interactions can be tested by these combined experimental methods.